Marijuana use can lead to a driving under the influence (DUI) charge in Maryland. This is true even though adults age 21 and older can legally possess and use certain amounts of cannabis. But driving while impaired by marijuana is still illegal. If you're facing a DUI charge for weed in 2026, our Chevy Chase, MD DUI defense lawyers can help you understand what you're up against and build a strong defense.
Under Maryland Transportation Article Section 21-902 (c), it's illegal to drive or attempt to drive while impaired by any drug, including marijuana. This also applies to a combination of drugs and alcohol. Marijuana impairment falls under the same broad DUI framework used for alcohol because of this – even though marijuana affects the body differently and doesn't have a simple breath test to measure impairment. In fact, these cases often rely on different types of evidence entirely.
There's no roadside breath test for marijuana the way there is for alcohol. Because of this, officers typically rely on field sobriety tests, their own observations of your driving and behavior, and sometimes blood tests conducted after your arrest. This makes marijuana DUI cases more subjective than alcohol cases in many ways.
An officer might point to things like the smell of marijuana, red or watery eyes, or slowed reaction time as signs of impairment. These observations can be challenged. Many of these signs can also result from other causes entirely unrelated to marijuana use.
THC can remain in your bloodstream for days or even weeks after use, unlike alcohol. This is true long after any actual impairment has worn off. This means a blood test showing THC in your system doesn't necessarily prove you were impaired at the time you were driving. For an experienced attorney, this offers an opportunity to challenge this type of evidence in court.
Unfortunately, having a valid medical marijuana card doesn't protect you from a DUI charge. Maryland law focuses on whether you were actually impaired while driving. It doesn't focus on whether your marijuana use was legal or medically authorized. This means patients using marijuana for legitimate medical reasons can still face DUI charges if police believe they were impaired behind the wheel.
Building a strong defense against this type of charge often depends on specific evidence and arguments. Helpful evidence includes:
Documentation showing when you last used marijuana relative to when you were driving
Records of your prescribed medical marijuana use, if applicable
Video footage from the traffic stop showing your actual behavior and coordination
Expert testimony explaining how THC blood levels don't directly correlate to impairment
Witness statements describing your behavior before you were pulled over
This type of evidence can help challenge the state's claim that you were actually impaired. It shows you simply had marijuana in your system at some point instead.
Challenging sobriety testing is often one of the most important parts of building a DUI defense. Field sobriety tests were originally designed with alcohol impairment in mind. Researchers and legal experts alike have questioned their reliability for detecting marijuana impairment specifically.
Factors like nervousness, medical conditions, fatigue, or even uneven pavement can affect performance on these tests. This is true regardless of whether marijuana played any role at all.
Maryland has specific penalties for driving while impaired by drugs. A first offense can result in up to two months in jail, a fine of up to $500, or both. A conviction can also result in driver's license consequences.
Penalties can become more serious for repeat DUI offenses or when impaired driving causes a serious injury. For example, a second offense can result in up to a year in prison and a $500 fine.
A defense attorney can challenge the reliability of field sobriety tests and blood test evidence, question whether the officer had a valid reason for the stop, and show that THC presence alone doesn't prove actual impairment.
At Diamant Gerstein, LLC, our attorneys personally answer your calls, not a receptionist. We're proud of our strong community ties as lifelong residents of Montgomery County, and we take a very hands-on approach with every client. Contact us at 301-560-2685 to talk to our Chevy Chase DUI defense lawyers today.
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